1. Field of the Invention
The present invention relates to a photosensitive material processing apparatus and a pleated cartridge filter that maintains stable processing performance by purifying a processing solution charged in a processing tank in which the photosensitive material is immersed.
2. Description of the Related Art
Photosensitive material processing apparatus for forming images on a variety of photosensitive materials, such as silver photographic photosensitive material (color print), are generally being used.
In some of these apparatus, a color print is obtained by successively immersing exposed photosensitive material (color print) in developing solution within a color developer tank, in bleaching-fixing solution within a bleaching-fixing tank, and in water within a rinsing tank, to thereby successively color develop, bleach-fix, and rinse the photosensitive material while the photosensitive material is conveyed at a predetermined speed.
As shown in FIG. 33, in the prior art there are photosensitive material processing apparatus disposed with a processing solution tank 100 (such as a color developing tank, a bleaching-fixing tank or a rinsing tank) for storing a processing solution into which the photosensitive material is immersed.
The processing solution tank 100 includes a substantially rectangular tank body 102 for storing a predetermined processing solution therein and a rack 104 that is detachably mounted within the tank body 102 and immersed in the processing solution.
The processing rack 104 is configured so that the photosensitive material is subjected to desired processing while the photosensitive material is immersed in the processing solution in the tank body 102 and conveyed along a U-shaped conveyance path by conveyance rollers.
The tank body 102 includes a subtank 106 that is integrally mounted to an upper part of a vertical side wall 102A. A drainage port 108 leading to the interior of the subtank 106 is disposed in the vertical side wall 102A at a position vertically lower by a predetermined distance from the surface of the processing solution stored in the tank body 102. The drainage port 108 drains processing solution in the tank body 102 to the subtank 106.
The subtank 106 includes a bottom that communicates with an opening at one end of a circulatory conduit 110, and a filter 112 is disposed at the opening. An opening at the other end of the circulatory conduit 110 communicates with a central portion at the bottom of the tank body 102.
The circulatory conduit 110 is formed as a series of conduits allowing communication between the bottom of the subtank 106 and the central bottom portion of the tank body 102.
The circulatory conduit 110 is successively disposed, from the subtank 106 towards the tank body 102, with a heater 114 and a pump 116.
By driving the pump 116, processing solution in the upper region of the tank body 102 is drawn into the subtank 106 through the drainage port 108, and is sucked into the circulatory conduit 110 through the filter 112. The filter 112 purifies the processing solution of the tank 100 by removing dust particles from the processing solution.
Processing solution sucked into the circulatory conduit 110 is heated to a predetermined temperature by the heater 114 and pressurized by the pump 116, and then it is discharged from the opening in the central portion of the bottom of the tank body 102 to the lower region of the tank body 102. The discharged processing solution rises from the lower region of the tank body 102 to the upper region of the tank body 102, whereby the processing solution is circulated.
Namely, processing solution in the tank 100 is discharged from the circulatory conduit 110 to the lower region of the tank body 102, flows upwards from the lower region of the tank body 102 to the upper region of the tank body 102, flows though the drainage port 108 into the subtank 106, and is then sucked through the filter 112 into the circulatory conduit 110, whereby the filter 112 removes dust particles and purifies the processing solution.
In this type of system for circulating and purifying processing solution in the tank 100, processing solution that is discharged from the opening, which has a small sectional area, of the circulatory conduit 110 in the bottom surface of the tank body 102 rises at a remarkably low velocity from the lower region of the tank body 102 to the upper region of the tank body 102, which has a large sectional area.
Therefore, microparticles, such as dust particles that are not removed by the filter 112 and become mixed in the processing solution in the tank body 102, settle at the bottom of the tank body 102 and remain in a floatable condition on the bottom surface of the tank body 102.
If the processing rack 104 is mounted or removed while such particles are in a floatable condition on the bottom surface of the tank body 102, the particles that have accumulated on the bottom surface of the tank body 102 rise up in the processing solution and adhere to the surface of the photosensitive material, whereby the photosensitive material may sustain damage as it is conveyed by conveyance rollers or the like.
There are photosensitive material processing apparatus disposed with horizontal multiple-chamber processors (disclosed in Japanese Patent Application Laid-open Publication (JP-A) No. 2000-258881) that are partitioned by blades in order to expedite rapid processing of the photosensitive material. When the processing solution in the tank body 102 is circulated or when the processing rack 104 is mounted or removed, dust particles floating in the processing solution may adhere to the blades and damage the surface of the photosensitive material as the photosensitive material makes sliding contact with and passes over the blades. When the photosensitive material is processed with its emulsion surface facing down, dust particles floating in the processing solution may adhere to the emulsion surface, whereby the surface of the photosensitive material may be scrubbed by the dust particles and damaged as it makes sliding contact with and passes over the blades.
Additionally, when processing solution that has been purified by the filter 112 and heated and temperature-adjusted by the heater 114 rises up from the circulatory conduit 110 opening in the bottom surface of the tank body 102 at an extremely low flow velocity towards the upper region of the tank body 102, it becomes easy for irregularities in the flow of the processing solution to arise because the processing solution rises up along a substantially fixed course from the lower region of the tank body 102 to the upper region of the tank body 102.
Thus, the heated and temperature-adjusted processing solution is mixed with some of the processing solution in the tank body 102, whereby the temperature of and distribution of components in the entire processing solution in the tank body 102 becomes uneven.
When the photosensitive material is immersed in and processed by processing solution within the tank body 102 whose temperature and component distribution have become uneven, developer streaks can appear in the photosensitive material.
Recently, in response to the increasing demand for rapid processing of photosensitive material, there have been proposed photosensitive material processing apparatus of a submerged conveyance system using a blade (e.g., JP-A No. 4-281452).
However, it has been found that, in such photosensitive material processing apparatus using a blade, dust particles up to 30 microns in size do not cause damage even if they are present in the processing solution while the photosensitive material is being processed.
Therefore, there has been proposed a plastic filter that is sintered and molded with resin particles finer than those of the prior art, as disclosed in Japanese Patent No. 3145649.
However, because the amount of dust particles to be filtered out increases in plastic filters that have been sintered and molded of fine resin particles without increasing the filtration area, the lifetime becomes shorter than that of the prior art.
It is conventionally known that a pleated filter can be used to increase the filtration area. However, there has not been proposed a simple and inexpensive pleated filter that can be reliably sealed without using an O-ring or packing ordinarily used for a fitting portion.
It is an object of the present invention to provide a photosensitive material processing apparatus that can maintain stable processing performance for forming damage-free images on photosensitive material by preventing dust particles and the like floating in processing solution stored within a processing tank from settling at the bottom of the tank and remaining in a floatable condition, and by suppressing damage to photosensitive material caused by dust floating up in the processing solution.
Another object of the invention is to provide a photosensitive material processing apparatus that can maintain stable processing performance for forming images free from developer streaks by circulating processing solution, which is purified, heated and temperature-adjusted, so that the processing solution is distributed all throughout a processing solution tank and uniformly mixed to make uniform the overall temperature of and distribution of components in the processing solution.
Still another object of the invention is to provide a photosensitive material processing apparatus and a pleated cartridge filter that has a longer lifetime than those of conventional sintered resin filters and that can be reliably sealed without using known O-rings or packing in a fitting portion.
According to a first aspect of the present invention, there is provided a photosensitive material processing apparatus including a tank that has a body charged with a solution that processes the photosensitive material, the apparatus comprising: a filter for purifying the processing solution; and a conduit for circulating the processing solution from a lower region of the tank body to an upper region of the tank body.
According to a second aspect of the invention, there is provided a photosensitive material processing apparatus including a tank that has a body charged with a solution that processes the photosensitive material, the apparatus comprising: a filter disposed on an inner bottom surface of the tank body; and a conduit for circulating the processing solution passing through the filter from a lower region of the tank body to an upper region of the tank body.
According to a third aspect of the invention, there is provided a photosensitive material processing apparatus including a tank that has a body charged with a solution that processes the photosensitive material, the apparatus comprising: an auxiliary chamber formed integrally with a bottom surface of the tank body; a filter that covers an opening in the auxiliary chamber; and a conduit for drawing processing solution that has passed through and been purified by the filter from a lower region of the tank body and sending the processing solution to an upper region of the tank body, to thereby circulate the processing solution charged in the tank body from the upper region to the lower region.
According to a fourth aspect of the invention, there is provided a photosensitive material processing apparatus including a tank that has a body charged with a solution that processes the photosensitive material, the apparatus comprising: a plate-shaped filter that covers an entire bottom surface of the tank body and is spaced apart from the bottom surface; and a conduit for drawing the processing solution from an opening in the bottom surface of the tank body up through the filter to purify the processing solution and for sending the processing solution to an upper region of the tank body, to thereby circulate the processing solution charged in the tank body from the upper region to a lower region.
According to a fifth aspect of the invention, there is provided a photosensitive material processing apparatus including a pump and a tank that has a body charged with a solution that processes the photosensitive material, the apparatus comprising: an auxiliary chamber formed integrally with a bottom surface of the tank body; a filter that covers an opening in the auxiliary chamber and is disposed such that an outer peripheral surface of the filter is positioned at a distance D in mm from an inner peripheral surface of the auxiliary chamber, with D being greater than 0.23X+2.5, X representing actual flow rate in liters/minute of the pump; and a conduit for drawing the processing solution that has passed through and been purified by the filter from a lower region of the tank body and sending the processing solution to an upper region of the tank body, to thereby circulate the processing solution charged in the tank body from the upper region to the lower region.
According to a sixth aspect of the invention, there is provided a photosensitive material processing apparatus including a tank that has a body charged with a solution that processes the photosensitive material, the apparatus comprising: a filter for purifying the processing solution; a subtank disposed on an outer side of a vertical side wall of the tank body and having a depth of at least one half that of the tank body; a plurality of through holes disposed on the vertical side wall between the tank body and the subtank; and a path for drawing processing solution from a lower region of the tank body through the filter and sending the processing solution to the subtank, and then passing the processing solution from the subtank through the through holes so that the processing solution flows evenly into the tank body from the subtank, to thereby uniformly mix the processing solution in the tank body.
According to a seventh aspect of the invention, there is provided a photosensitive material processing apparatus including a tank that has a body charged with a solution that processes the photosensitive material, the apparatus comprising: a filter for purifying the processing solution; a subtank disposed on an outer side of a vertical side wall of the tank body and having a depth of at least one half that of the tank body; a plurality of through holes disposed on the vertical side wall between the tank body and the subtank; a plurality of through holes disposed in a vertical side wall of a processing rack in the tank body at positions facing and corresponding to the through holes formed in the vertical side wall of the tank body; and a path for drawing processing solution from a lower region of the tank body through the filter and sending the processing solution to the subtank, and then passing the processing solution from the subtank through the through holes so that the processing solution flows evenly into the tank body from the subtank, to thereby uniformly mix the processing solution in the tank body.
According to an eighth aspect of the invention, there is provided a photosensitive material processing apparatus including a tank that has a body charged with a solution that processes the photosensitive material, the apparatus comprising: a filter for purifying the processing solution; a subtank disposed on an outer side of a vertical side wall of the tank body and having a depth of at least one half that of the tank body; a plurality of through holes disposed across a vertical range in the vertical side wall between the tank body and the subtank; and a path including branch pipes corresponding to the through holes, the path drawing the processing solution from a lower region of the tank body through the filter and sending the processing solution through the branch pipes corresponding to the through holes so that the processing solution flows evenly into the tank body, to thereby uniformly mix the processing solution in the tank body.
According to a ninth aspect of the invention, there is provided a photosensitive material processing apparatus including a tank that has a body charged with a solution that processes the photosensitive material, the apparatus comprising: a filter for purifying the processing solution; a subtank disposed on an outer side of a vertical side wall of the tank body and having a depth of at least one half that of the tank body; a through hole formed in a slit shape from an upper part of the vertical side wall to a lower part of the vertical side wall between the tank body and the subtank, with the sectional area of the through hole gradually becoming smaller from the upper part of the vertical side wall to the lower part of the vertical side wall; and a path for drawing processing solution from a lower region of the tank body through the filter and sending the processing solution to the subtank, and then passing the processing solution from the subtank through the slit-shaped through hole so that the processing solution flows evenly from a top part of the subtank to a bottom part of the subtank and into the tank body, to thereby uniformly mix the processing solution in the tank body.
According to a tenth aspect of the invention, there is provided a pleated cartridge filter for use in a photosensitive material processing apparatus including a processing tank charged with a solution that processes photosensitive material, a device for circulating the processing solution, and a fitting portion that is disposed in the circulation device and to which a filter for removing dust particles from the processing solution is fitted, the cartridge filter comprising: a cylindrical pleated filter body formed by folding a filtering sheet member; and a blocking member, including a hole that communicates between an interior of the filter body and the outside, for blocking at least one end of the filter body, wherein a portion of the blocking member contacting the fitting portion is compressed when the blocking member is fitted to the fitting portion to closely contact the same.
According to an eleventh aspect of the invention, there is provided a photosensitive material processing apparatus comprising: a processing tank charged with a processing solution that processes photosensitive material; a device for circulating the processing solution; and a fitting portion to which the pleated cartridge filter provided in the tenth aspect is fitted, wherein the fitting portion is recessed, with an aperture in a vicinity of an opening in the recess being 0.5 to 3.0% larger than an external diameter of the portion of the pleated cartridge filter that contacts the recess.